A324594 a(n) is the smallest number k such that n consecutive integers starting at k have the same number of nonprime divisors (A033273).

1, 1, 1, 19940, 204323, 294590, 310042685, 2587701932494, 2587701932494

Offset

1,4

Links

Table of n, a(n) for n=1..9.

Rémy Sigrist, C program for A324594

Example

19940 has 9 nonprime divisors {1, 4, 10, 20, 1994, 3988, 4985, 9970, 19940}, 19941 has 9 nonprime divisors {1, 51, 69, 289, 391, 867, 1173, 6647, 19941}, 19942 has 9 nonprime divisors {1, 26, 118, 169, 338, 767, 1534, 9971, 19942} and 19943 has 9 nonprime divisors {1, 49, 77, 259, 407, 539, 1813, 2849, 19943}. These the first 4 consecutive numbers with the same number of nonprime divisors, so a(4) = 19940.

Prog

(C) See Links section.

Crossrefs

Cf. A006558, A033273, A045983, A045984, A323253, A324593.

Sequence in context: A237564 A171353 A175590 * A203045 A307474 A206009

Adjacent sequences: A324591 A324592 A324593 * A324595 A324596 A324597

Keyword

nonn,more

Author

Ilya Gutkovskiy, Sep 03 2019

Extensions

a(7) from Rémy Sigrist, Sep 04 2019

a(8)-a(9) from Giovanni Resta, Sep 04 2019

Status

approved